• 대한예방의학회:학술대회논문집
• /
• 1997.10b
• /
• pp.220-222
• /
• 1997

• Journal of the Korean Society of Safety
• /
• v.32 no.2
• /
• pp.117-123
• /
• 2017

This study was intended to find methods of fire extinguishing system designs that can improve the equipment's usability. In this study, the fire suppression experiment through fire extinguishers and the data drawn through the experiment were analyzed, and then the guideline for the improvement of designs was presented. The procedure is as follows. A fire suppression experiment with the use of fire extinguishers was done by 43 average adults. The whole process of the fire suppression was videotaped, and then captured major scenes were analyzed with the use of RULA, a human engineering measurement tool. The analyzed data were divided into 4 steps, and then the guideline for design improvement was presented. The summary of the study is as follows. Step 1, Fire extinguisher distance step. To reduce overload occurring at the process of holding fire extinguishers suddenly, wheels are attached to the body of extinguishers, or pedestals are installed. Step 2, Fire extinguisher transportation step. The length of hose is extended, or fire fighting water is sprayed far, so that overload of legs occurring at the process of travel can be reduced. In addition, the weight of fire extinguisher shouldn't be over 2 kg. Step 3, Safety pin removal stage. Safety pins should be applied with button type, so that excessive posture of lower limbs and excessive twisting of wrists won't happen during safety pin removal process. Besides, safety pins should be designed for easy identification and operation. Step 4, Fire extinguishing agent spraying step. To reduce overload occurring at sudden spraying of fire fighting water, pressure should be increased gradually until high pressure. With the above study results applied to existing fire extinguisher design, it may contribute to reducing any fire damage.

• Journal of the Korea Safety Management & Science
• /
• v.14 no.2
• /
• pp.123-136
• /
• 2012

The validity of the results from observational methods such as RULA, REBA, OWAS has been one of major concerns due to their subjective characteristics in determining the posture of interests. There have been many studies regarding validity of the results from each checklist. However, most studies provided only fragmentary rather than comprehensive results in nature. This study specifically tried to analyze consistency of novice user based on intra-observer consistency and sensitivity of industrial types during MSDs(Musculoskekltal Disorders) evaluation with major checklists. In this study, twenty two novice subjects were participated to conduct MSDs evaluation for the forty five jobs from three types of industries(automobile, electronics, hospital). The main results for this study were summarized as follows; 1) The action level based on RULA was always higher than that from REBA and OWAS for all three types of industries., 2) The order of consistency from novice users was OWAS(72.7%(kappa=0.57)) RULA(54.3%(kappa=0.41)), REBA(41.0%(kappa=0.34))., 3) The percentage of agreement between 2nd and 3rd trials was higher than those between 1st and 2nd trials and between 1st and 3rd trials irrespective of industrial types during using RULA and REBA., 4) The average score of automobile industry was higher than those of hospital and electronics industries., 5) The types of jobs associated with five body parts(A1(Front), A2(Interior), A3(Rear), A4(Lower), A5(Door)) in automobile industry showed statistically significant differences in terms of MSDs scores for the body parts considered in each checklists.

• Journal of the Korean Society of Industry Convergence
• /
• v.14 no.1
• /
• pp.29-36
• /
• 2011

This study analyzed the convenience and productivity before and after adopting self-propelled power transportation devices to the harvest and transportation of fruit and vegetable products in the Gyeongbuk region, by applying the REBA and RULA techniques. In the REBA analysis, the work risk was low with 4~6 points before adoption which became 2~3 points after adoption. As for the RULA analysis, work loading appeared to have decreased with 6~7 points before adoption which became 3~4 points after adoption. The annual work time reduction was about 48~179 hours while labor costs were reduced to 364~1,345 thousand won annually. This indicated a labor cost reduction effect of about 10~15%. Therefore, the adopted self-propelled power transportation devices appeared to prevent musculo skeletal diseases of the human body and also improve productivity even after using it for long hours according to the REBA, RULA measures level.

• Journal of the Ergonomics Society of Korea
• /
• v.26 no.2
• /
• pp.81-88
• /
• 2007

The objective of this study was to investigate the validity of the digital ergonomic simulation (DES) method as a prospective alternative to the ergonomic analyses conducted by experts. The DES method utilizes commercial digital manufacturing software, and can compute the RULA scores continuously throughout the simulated work cycle. It was shown in a case study that the accuracy and objectivity of the DES method are superior to those obtained by experts. Also, it was demonstrated that the DES method has a distinct capability to simulate and validate a proposed work plan. Major limitations of the current DES method lie in the extensive time and efforts required for accurate digital simulation, which may be overcome through an automatic module for RULA data acquisition and a motion capture system.

• Journal of the Ergonomics Society of Korea
• /
• v.32 no.3
• /
• pp.273-278
• /
• 2013

Objective: This study aims to analyze and evaluate fatigue in upper trapezius muscles of adults when inputting text on a smart phone, thereby examining the risk of cumulative trauma disorders in the musculoskeletal system of the upper extremity. Method: Forty-five healthy adults were divided equally into three groups: a smartphone group, a notebook group, and a desktop group. A surface electromyogram was placed on the upper trapezius muscle of each participant, after which they inputted text for ten minutes within an ergonomic setting; their side posture was recorded on video and analyzed. Results: The spectral edge frequency values for the smartphone group, as recorded from the upper right trapezius muscles on the surface electromyogram, showed a significant decrease(p<.05). Regarding the RULA, all three groups had results indicating "action level 2". Conclusion: All three groups had results indicating "action level 2" according to the RULA, which means that additional research on the posture of the participants while performing tasks is necessary, and their posture needs to be corrected. In particular, the smartphone group has the highest levels of fatigue in the upper trapezius muscles, suggesting that the task of inputting text on a smartphone is a high risk for causing cumulative trauma disorders.

• Journal of Biomedical Engineering Research
• /
• v.17 no.4
• /
• pp.469-478
• /
• 1996

In the conventional digital ultrasound scanner, the reflected signal is sampled either in polar coordinates of R-$\theta$ method, or in Cartesian coordinates of uniform ladder algorithm (ULA). The R-$\theta$ scan method necessitates a coordinate transform process which makes hardware complex in comparison with ULA scan mrthoA In spite of this complexity, R-$\theta$ method has a good resolution in ultrasonographic (US) image, since scan direction of the US imaging is a radial direction. In this paper, a new digital scan converter is proposed, which is named the radius uniform ladder algorithm (RULA). The RULA has the rome scan direction as the US scanning in the radial direction and as the display space in the $\theta$ direction. In tllis new approach, sampled points we uniformly distributed in each horizontal line i.n well as in each radial ray so that the data are displayed in the Cartesian coordinates by the 1-D interpolation process. The propped algorithm has an uniform resolution in the periphery and the center field in comparison with equi-angle ULA and equi-interval ULA. To extend the scan angle, concentric square raster sampling (CSRS) is adopted with reduction of discontinuities on the junctions between horizontal scan and vertical scan. The discontinuities are reduced by using the hmction filtering along the $\theta$ direction.

• Journal of Korean Society of Forest Science
• /
• v.110 no.2
• /
• pp.210-216
• /
• 2021

Musculoskeletal disorders affect workers' safety in most industries, and forest operations are classified as a musculoskeletal burden according to the Occupational Safety and Health Act in South Korea. In particular, felling and delimbing operations are mainly conducted by manpower, and then, it is necessary to evaluate ergonomic risk assessment for safety of felling and delimbing workers. Three ergonomic risk assessment methods, such as Ovako Working posture Analysis System (OWAS), Rapid Upper Limb Assessment (RULA), and Rapid Entire Body Assessment (REBA), are available for assessing exposure to risk factors associated with timber harvesting operations. Here, three ergonomic risk assessment methods were applied to examine ergonomic risk assessments in chainsaw felling and delimbing operations. Additionally, exposure to risk factors in each method was analyzed to propose an optimal working posture in felling and delimbing operations. The risk levels of these operations were evaluated to be highest in the RULA method, followed by the OWAS and REBA methods, and most of the exposed working postures were examined with a low-risk level of two and three without requiring any immediate working posture changes. However, two significant working postures, including the bending posture of the waist and leg in felling operation and standing posture on the fallen trees in delimbing operation, were assessed as the high-risk level and needed immediate working posture changes. Low-risk work levels were examined in the squatting posture for felling operation and the straightened posture of the waist and leg for delimbing operation. Moreover, the slope in felling operation and the tree height in delimbing operation significantly affected risk level assessment of working posture. Therefore, our study supports that felling and delimbing workers must operate with low-risk working postures for safety.

• Journal of Biosystems Engineering
• /
• v.35 no.3
• /
• pp.206-213
• /
• 2010

The purpose of this study is to analyze musculoskeletal injuries in combine harvesting operation using a digital human model. In order to analyze problems in combine harvesting operation, the operations were broken into 5 work processes and then we preformed ergonomic and biomechanical analyses such as RULA test, Comfort Assessment and joint kinetic analysis for the each process. As a result, there was a clear need to change the combine operating environment, as the RULA score ranged from 4 to 7. In addition, we could find two major musculoskeletal injury factors which are the standing posture with upperbody forward tilting and inappropriate location of operating levers.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2006.05a
• /
• pp.603-604
• /
• 2006

The worker who is responsible for Airless Pump maintenance have a high possibility to suffer from WMSDs, because a height of Airless Pump workbench is too low. In this paper, I'm going to introduce a research about 1) analysis of working environment through a interview with an actual field worker, 2) Ergonomic simulation modeling of an Ariless Pump worker to suggest a advanced working environment and a working instructions. I have used a DELMIA S/W as a tool for ergonomic simulation and performed a posture & activity to analyze a RULA methodology. Applying the Digital Human Simulation to analyze working posture would be helpful to preventing WMSDs.